The extra levy has been introduced to tackle the capital's growing air pollution problem, and targets pre-Euro 4 petrol and diesel vehicles manufactured before 2005 that don't meet Euro 4 emissions standards for nitrogen oxide and particulates.

Transport for London has launched a free online vehicle checker so drivers can see if the T-charge will affect them.

The T-charge is being policed by the same network of cameras that already govern London's congestion charging zone.

Cleaning up the capital

Khan's aggressive stance to cut urban emissions has seen him also propose an extension of the planned Ultra Low Emissions Zone (ULEZ) to include the North and South Circular roads - a move that would dramatically extend the zone's extremities. Under current plans, drivers entering the ULEZ will have to pay a charge depending on how clean their vehicle is from 2020, but Khan has now said he wants to bring that date forward by one year.

The capital already has a Low Emission Zone, but this does not currently apply to cars or motorbikes.

Elsewhere, a set of 'clean bus corridors' have been proposed, which would see the cleanest buses placed on the dirtiest road routes in a bid to tackle emissions. Khan has also given Transport for London (TfL) the green light to investigate whether a diesel scrappage scheme could work in the capital. The scheme, which would offer cash incentives to diesel drivers to encourage them to choose a cleaner car, has previously been shot down by MPs, who claimed it would be ineffective and expensive to manage.

When he initially announced the plans last year, Khan said he wanted to act "before an emergency, which is why we need big, bold and sometimes difficult policies if London is to meet the scale of the challenge.

"I have been elected with a clear mandate to clean up London's air. The previous mayor was too slow on this issue, the government has been hopelessly inactive and it's Londoners who are suffering as a result."

Khan cited medical research, which claims that more than 10,000 people die annually in London due to polluted air. London's air quality has come under close scrutiny in recent years, particularly in relation to NOx emissions. Parts of the capital regularly breach EU limits for NOx; Putney High Street in West London breached the EU's annual limit just one week into 2016.

Despite his tough stance on pollution, Khan's proposals aren't the country's hardest. Oxford City Council is pushing for petrol and diesel cars to be banned from its urban centre from 2020. The policy is currently being subjected to a public consultation.

Personal mobility frightens those on the Left as it means people are allowed to have an independent thought as to where and how they travel. That is why they champion autonomous driving (where the government will control the routes and speed limits but will still ticket you if you decide to have a drink before letting your car drive you safely home)and battery-powered cars that force you to stop for much-longer periods to fill up than petrol to make it feel that you are wasting your time going anywhere too far if you aren't on a train or a bus. However, just like with all regulations, if you have money it solves the problem. Thus, you will be stuck on public transport while the government ministers swan about in high-end vehicles. Not unlike the Soviet Union really whose government folks also hated people with independent thoughts.

Wow do you have your tin foil hat on ?!
I think we should be stopping high polluting vehicles in London rather than still allowing them albeit with a charge.
There should be better incentives to drivers buying electric vehicles - our govt cut that incentive last year.
Car free days are the norm in other major capitals but London lags behind.
I lived in West London for 20 years and rarely if ever needed to drive in the congestion zone area. Love it or hate it the TFL network runs well meaning London car ownership is not a high priority for most